Classic Car And Truck Restoration
64-1/2,65 Mustang Generator to Alternator Swap
     One of the major mechanical differences between the 64-1/2 Mustang and the 65 Mustang is that the early production cars were equipped with a generator charging system. Most Mustangs built after August of 1965 had alternator-charging systems. In both cases output amps were a low 35-43 amps, fine “Back in the day” for running the options available at the time. Now with halogen lights, modern high amp sound systems, aftermarket air conditioners, electric cooling fans, these old units just can’t keep the battery charged. Outlined below are the steps to swap a generator to higher output alternator.
1. Select an altermator with at least 60 amps output
2. Select a  stock wired Alternator
3. Match the pulley system of your car
4. Voltage Regulator  matched to alternator amp output 
5. Installation is the same as the generator
6. This diagram matches my car's  actual wiring  colors
     if yours is different just follow connection regardless       of color
7. You may need a longer fan belt
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Generator and Alternator
Generator bracket on top Alternator bracket on bottom
Generator bracket on left, Alternator on right. The alternator bracket may have a small offset, it needs to be flat.
Aluminium spacer for the alternator, get this from the wrecking yard along with the alternator. The flattened area is about 1": wide the will provide clearance for the bracket bolts
This is the generator bracket. The middle holes are original. 2 new holes neet to be drilled 2-5/8" from the front and 2-5/8" apart. Bolts are shown in the proper location.

I needed to enlongate the holes slightly to provide some adjustment fore and aft. Use a straight edge across the face of the crankshaft pulley to the face of the alternator pulley to align the alternator.
Side View of the assembled bracket . Note how close the bolts are to the spacer. You will need a 7/16" x 6-1/2" or 7" bolt as the original bolt for the alternator was to short.
Parts Catalog
Chassis Dimensions
64-65 Gallery
Tune Up Specs
66 Gallery
Interior Codes
EFI Swap
Rack & Pinion
64-1/2 Wiring Diagram
65 Wiring Diagram
66 Wiring Diagram
Duraspark Conversion
Charging System
Modification Log
8" Rearend Swap
6 Gauge Cluster